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  • How To Learn The Basics Of C++ Part 2/5
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Oct 8, 2011 (last update: Oct 8, 2011)

How To Learn The Basics Of C++ Part 2/5

Score: 3.9/5 (278 votes)
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Greetings Fellow Programmers,

So far we've learned about the basic components of starting and running a basic program:
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#include <iostream>
using namespace std;
int main (void){

// Code Goes Here

return 0;
}


In this tutorial we'll be learning about basic input and output statements, and the types of variables you can use when you make a program. This will make our programs a little bit more "user-interactive", instead of just displaying text(or prompts) on the screen.

To start off, make sure you have the basic starting components to your program:

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#include <iostream>
using namespace std;
int main (void){

// Code Goes Here (You do not need to put this, it's optional)

return 0;
}


Withing the two curly braces, delete the comment (It was acting as a placeholder, it's useless to us now), and type the following:
 
cout << "Please enter a number." << endl;

Your probably wondering what endl is. Well, it just tells the compiler that, after this piece of text (or statement) is executed, I want a brand new line(Basically, going to the next line under the previous line executed).

After you've entered the code above proceed to writing:
 
cin >> number;

right underneath the cout (CEE-OUT) statement you've just made.

Your code should look exactly like this:
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#include <iostream>
using namespace std;
int main (void){

cout << "Please enter a number" << endl;
cin >> number;

return 0;
}


cin, is the statement you use to collect user-input from the user. It's a great way to keep your program exciting.

Our program is still not complete though. We have yet to tell the compiler what data type "number is". Well, this is a bit complicated and it would be best if you could commit these terms to memory:

VARIABLE TYPES:

1. Boolean (bool): This keyword is generally used for variables that are equal to true or false in your program.

2. Character (char): This keyword is used for characters. It can only hold one character such as an "A".

3. Integer (int): This keyword is used for numbers like 5,455, and so on. There are some regulations (which I will explain in the next tutorial), but for now just know the definition and context of when to use it.

These are the basic variable types and I highly suggest that you memorize them.
Go ahead and add, right before your "cout" statement:
int number; After you've added this go right under your "cin" statement and put:

cout << "You typed in " << number << "!" << endl;
Be sure to write that "cout" statement just like that. Also, whenever you want to display a variable on screen you type:

cout << (Whatever your variable name is)<< endl;
So now your program should look like this:
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#include <iostream>
using namespace std;
int main (void){
int number;

cout << "Please enter a number" << endl;
cin >> number;
cout << "You typed in " << number << "!" << endl;
return 0;
}


When you run your program you should get:

Please enter a number
(It'll wait for your number here...)
40
You typed in 40 (It displays your number here!)

Stay Tuned for Part 3! :)
May the code be with you...